A stanza sent between two servers lacks a 'to' or 'from' attribute, or the attribute values are invalid with respect to the stream addresses. This is a stream-level error that terminates the stream.
stream-improper-addressing
xmpp A stanza sent between two servers lacks a 'to' or 'from' attribute, or the attribute values are invalid with respect to the stream addresses. This is a stream-level error that terminates the stream.